1. Cachalot Whale will despawn suddenly. It may even despawn when it's right in front of you. However, the two chunks don't seem to despawn even if they are far away. Also, it doesn't seem to despawn when it's white.

2. Cachalot Whales migrate more frequently to the southeast

3. There are times when it simply does nothing and remains still.

This is what I found out by making a 144x8x144 reservoir on a flat map.

mode : jei, world edit, alex mobs 1.22.9, citadel 2.6.1
forge version : 47.3.0